US vs FL-Guided Lumbar Nerve Root Injections

Ultrasound-Guided Versus Fluoroscopy-Guided Selective Lumbar Nerve Root Injections for Lumbosacral Radiculopathy: A Randomized Clinical Trial

The goal of this clinical trial is to learn if ultrasound-guided nerve root injections work as well as fluoroscopy (X-ray)-guided injections to treat lower back and leg pain caused by irritated nerves (lumbosacral radiculopathy) in adults aged 18 to 75 years old.

The main questions it aims to answer are:

• Does ultrasound guidance lower pain as effectively as fluoroscopy guidance after 3 months?
• Does one method help participants recover their ability to do daily activities better than the other?
• Are ultrasound-guided injections as fast and safe for participants as fluoroscopy-guided injections? Researchers will compare ultrasound-guided nerve root injections to fluoroscopy-guided nerve root injections to see if ultrasound works to treat the pain just as well while allowing participants to avoid radiation exposure.

Participants will:

• Receive one targeted nerve injection of medication (a steroid and numbing medicine) in their lower back using either ultrasound or fluoroscopy to guide the needle.
• Stay at the clinic for 30 to 60 minutes after the procedure so researchers can check their safety.
• Attend checkups at 1 week, 1 month, and 3 months to answer survey questions about their pain levels and daily functioning.

Study Overview

• Status: Recruiting
• Conditions: Lumbosacral Radiculopathy
• Intervention / Treatment: Procedure: Ultrasound-Guided Selective Lumbar Nerve Root Injection; Procedure: Fluoroscopy-Guided Selective Lumbar Nerve Root Injection

Detailed Description

Background and Rationale Lumbosacral radiculopathy is a common and disabling condition resulting from irritation or compression of spinal nerve roots. When conservative treatments fail, epidural steroid injections are a frequently employed non-surgical intervention. Traditionally, selective lumbar nerve root injections are performed under fluoroscopic (FL) guidance to ensure precise needle placement. However, fluoroscopy exposes patients and healthcare providers to ionizing radiation and has limitations in soft tissue visualization. Ultrasound (US) guidance has emerged as a viable alternative, enabling real-time visualization of soft tissues, nerves, and vascular structures while entirely eliminating radiation exposure. This randomized clinical trial aims to compare the efficacy, safety, and functional outcomes of US-guided versus FL-guided selective lumbar nerve root injections in patients with refractory lumbosacral radiculopathy.

Study Design and Randomization This is a single-center, parallel-group, randomized clinical trial with a 1:1 allocation ratio conducted at Tanta University Hospitals. Participants are randomly assigned to either the US-guided or FL-guided group using a computer-generated randomization sequence created via RANDOM.ORG. The sequence utilizes permuted blocks of varying sizes (4 and 6) to ensure balanced group allocation. Allocation concealment is maintained using sequentially numbered, opaque, sealed envelopes managed by an independent research coordinator. While patients and proceduralists cannot be blinded to the intervention, the outcome assessors and data analysts remain blinded to group assignment.

General Procedural Protocol Prior to the intervention, patients are positioned prone or lateral with lumbar exposure. Skin sterilization is performed, and a single dose of broad-spectrum parenteral antibiotic (cefazolin 1 g intravenous) is administered. For both study arms, the standardized injectate consists of a 3 mL total volume containing 1 mL corticosteroid (dexamethasone 4 mg), 1 mL local anesthetic (2% lidocaine), and 1 mL 0.9% sodium chloride.

Image-Guidance Protocols

• Ultrasound-Guided Technique: A posterior paravertebral ultrasound scan is performed using a curved transducer, followed by a transverse sonogram at the target site to identify the spinous process, vertebral lamina, facet joints, and intervertebral foramen. A 22-gauge spinal needle is advanced using an in-plane technique until mild paresthesia in the affected dermatome is elicited, followed by medication injection. No contrast agent is utilized in this arm.
• Fluoroscopy-Guided Technique: A C-arm fluoroscopy unit is used for visualization. A 22-gauge spinal needle is inserted into the safe triangle near the nerve root. Iodinated contrast material (iohexol 240 mgI/mL, 1-2 mL) is injected to confirm extra-vasculature, extra-thecal needle placement before the therapeutic medication is administered.
• L5-S1 Modification: For L5-S1 level injections in both groups, a modified approach is employed with the needle directed more laterally to access the lateral recess of the spinal canal, targeting the L5 nerve root as it courses toward the L5-S1 foramen.

Post-Procedure Care Following the injection, patients are monitored for 30 to 60 minutes to observe for any immediate complications, such as allergic reactions, bleeding, or neurological deficits. Discharge instructions include mandatory rest for 48 hours and the avoidance of strenuous physical activity. Follow-up assessments are conducted at 1 week, 1 month, and 3 months by the blinded independent assessors.

Statistical Analysis Plan The planned sample size is 64 patients (32 per group), calculated to provide 80% power to detect a 50% reduction in pain scores, accounting for an anticipated 15% dropout rate. Statistical analysis is performed on an intention-to-treat (ITT) basis. Missing data for the primary analysis are handled using multiple imputations by chained equations (MICE) under the assumption of missing at random, generating 20 imputed datasets. Continuous outcomes will be analyzed using analysis of covariance (ANCOVA) with baseline values included as covariates. Categorical responder analyses will also be conducted to evaluate the minimal clinically important difference (MCID) and substantial clinical benefit (SCB).

• Study Type: Interventional
• Enrollment (Estimated): 64
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ahmed S Alkotami, MD; Phone Number: +201008928948; Email: ahmed.sami@med.tanta.edu.eg

Study Locations

• Egypt
  • Gharbia Governorate
    • Tanta, Gharbia Governorate, Egypt, 31527
      • Recruiting
      • Faculty of Medicine, Tanta University.
      • Contact: Ahmed S Alkotami, MD; Phone Number: +201008928948; Email: ahmed.sami@med.tanta.edu.eg
      • Principal Investigator: Basem H Fouda, MD
      • Principal Investigator: Wafaa M Abdelwahed, MD
      • Principal Investigator: Elsayed E Negm, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adults aged 18 to 75 years.
• Clinical diagnosis of lumbar radiculopathy characterized by radicular pain, paresthesia, or weakness in a dermatomal distribution.
• Magnetic Resonance Imaging (MRI)-confirmed nerve root compression due to disc herniation or foraminal stenosis.
• Failure to respond to at least 3 months of conservative medical treatment.
• Radiculopathy affecting the L4, L5, or combined L5-S1 levels (where the primary symptomatic level can be reliably targeted)

Exclusion Criteria:

• Isolated S1 radiculopathy.
• Significant spinal deformities, including scoliosis >20° or spondylolisthesis >Grade II.
• History of prior lumbar spine surgery.
• Bleeding disorders (International Normalized Ratio [INR] >2.5).
• Severe uncontrolled diabetes mellitus (HbA1c >8%).
• Advanced cardiac, renal, or hepatic disease.
• Active systemic infection or localized infection at the injection site.
• Known allergies to corticosteroids or local anesthetics.
• Presence of progressive neurological deficits or cauda equina syndrome.
• Peripheral neuropathies mimicking radiculopathy.
• Pregnancy or breastfeeding.
• Severe psychiatric illness or cognitive impairment affecting study compliance.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Ultrasound-Guided Injection; Participants receive a selective lumbar nerve root injection under real-time ultrasound guidance. The injectate consists of a 3 mL total volume (1 mL dexamethasone 4 mg, 1 mL 2% lidocaine, and 1 mL 0.9% sodium chloride). No contrast agent is used.	Procedure: Ultrasound-Guided Selective Lumbar Nerve Root Injection; A posterior paravertebral ultrasound scan is performed using a curved transducer, followed by a transverse sonogram at the target site to identify the spinous process, vertebral lamina, facet joints, and intervertebral foramen. A 22-gauge spinal needle is advanced using an in-plane technique until mild paresthesia in the affected dermatome is elicited. The standardized therapeutic medication is then injected without the use of a contrast agent.
Active Comparator: Fluoroscopy-Guided Injection; Participants receive a selective lumbar nerve root injection under fluoroscopic guidance. Iodinated contrast material is injected to confirm placement, followed by the therapeutic injectate consisting of a 3 mL total volume (1 mL dexamethasone 4 mg, 1 mL 2% lidocaine, and 1 mL 0.9% sodium chloride).	Procedure: Fluoroscopy-Guided Selective Lumbar Nerve Root Injection; A C-arm fluoroscopy unit is used for visualization. A 22-gauge spinal needle is inserted into the safe triangle near the nerve root under fluoroscopic guidance. Iodinated contrast material (iohexol 240 mgI/mL, 1-2 mL) is injected to confirm extra-vasculature, extra-thecal needle placement and to rule out intravascular injection before the standardized therapeutic medication is administered.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Visual Analog Scale (VAS) Score	The Visual Analog Scale (VAS) is used to evaluate the intensity of radicular pain. It is a 10-cm horizontal line anchored at 0 representing "no pain" and 10 representing the "worst possible pain." Higher scores indicate greater pain intensity. This outcome reports the change in pain intensity from baseline to the 3-month follow-up.	Baseline and 3 months post-procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visual Analog Scale (VAS) Score at Short-Term Follow-up	The Visual Analog Scale (VAS) evaluates the intensity of radicular pain. It is a 10-cm scale where the minimum value is 0 ("no pain") and the maximum value is 10 ("worst possible pain"). Higher scores indicate greater pain intensity and a worse outcome.	1 week and 1 month post-procedure
Oswestry Disability Index (ODI) Score	The ODI is a questionnaire used to measure a patient's permanent functional disability. Scores range from a minimum of 0% to a maximum of 100%. Higher scores indicate greater disability and a worse outcome.	1 week, 1 month, and 3 months post-procedure
Total Procedural Time	The total time required to perform the injection procedure, measured in minutes from the start of skin preparation to the moment of needle withdrawal.	Intraoperative (Day 0)
Needle Adjustment Time	The specific duration of time, measured in minutes, required for adjusting and maneuvering the needle to reach the target site during the procedure.	Intraoperative (Day 0)
Patient Satisfaction Score	Patient satisfaction is evaluated using a 5-point Likert scale. The minimum value is 1 (extremely dissatisfied) and the maximum value is 5 (extremely satisfied). Higher scores indicate greater satisfaction and a better outcome.	3 months post-procedure
Analgesic Medication Requirements	The proportion of patients who continue to require the use of analgesic medications (such as NSAIDs or opioids) for pain management.	3 months post-procedure
Incidence of Complications and Adverse Events	The number of participants experiencing any procedural complications or adverse events, including but not limited to pain at the injection site, hematoma, vascular injury, neural injury, or infection.	Up to 3 months post-procedure

Collaborators and Investigators

• Sponsor: Tanta University

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2026
• Primary Completion (Estimated): July 31, 2026
• Study Completion (Estimated): October 30, 2026

Study Registration Dates

• First Submitted: May 31, 2026
• First Submitted That Met QC Criteria: May 31, 2026
• First Posted (Actual): June 4, 2026

Study Record Updates

• Last Update Posted (Actual): June 4, 2026
• Last Update Submitted That Met QC Criteria: May 31, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Radicular Pain; Lumbosacral Radiculopathy; Ultrasound-Guided; Fluoroscopy-Guided
• Other Study ID Numbers: 36264PR888/10/24

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Deidentified participant data and statistical code will be shared.
• IPD Sharing Time Frame: Beginning 12 months after publication.
• IPD Sharing Access Criteria: Available upon reasonable request to the corresponding author.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No